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H H PPP CCC UK NATIONAL HPC SERVICE
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HHHHH PPP C x x provided by
H H P C C xx EPCC and
H H P CCC x x CCLRC Daresbury Laboratory
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HPCx User Mailing 055 29 October 2004
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Contents
** Supercomputing
** Courses
** Change to password validation
** Attention PuTTY users!
** Bulletin Board
** "Capability Computing"
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Greetings--
SUPERCOMPUTING 2004
CCLRC Daresbury Laboratory and EPCC will have adjoining stands at the
Supercomputing 2004 event in Pittsburgh, PA, starting on 8 November,
and together we will be ensuring that HPCx has a presence. If anyone
is going - please stop in and visit us.
EPCC will be presenting a half-day tutorial, led by Lorna Smith and
Mark Bull of the HPCx Terascaling team, on "Perfromance Scaling on
Constellation Systems". The tutorial will draw on material developed
for HPCx training courses as well as experience on other clustered SMP
systems.
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COURSES
At CCLRC Rutherford Appleton Laboratory
Thursday Nov 25: Optimisation Techniques for the Power4 Processor
This course will focus on tools and techniques for single processor
optimisation on HPCx. The course will cover the architecture of the
processors and memory system, profiling and hardware counter tools,
getting the best from the compilers and Power4-specific tips and
tricks. There will be hands-on sessions in addition to lecture
material. We recommended that participants also attend the Performance
Scaling course which will be held on the following day.
Friday Nov 26: Improved Performance Scaling on HPCx
This course will describe tools and techniques for improving the
parallel scaling of applications on HPCx. The course will cover
performance analysis tools, communication optimisation, decomposition
techniques, parallel I/O, and mixed mode programming. There will be
hands-on sessions in addition to lecture material. We recommended that
participants also attend the Optimisation Techniques course which will
be held on the previous day.
To register for these courses, please use the standard form.
http://www.hpcx.ac.uk/support/training/form.html
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CHANGE TO PASSWORD VALIDATION
Until recently, accounts on HPCx were blocked after three failed
attempts to log in. This limit has now been changed to ten. However,
after each three failures, you will have to reconnect. We are
confident that this change will not significantly affect the security
of the service. On the other hand, looking at the query logs, it's
clear that it has resulted a welcome reduction in the number of
problems that people have with logging in.
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ATTENTION PuTTY USERS!
Many people who access HPCx through a PC use the PuTTY program to make
their connection to HPCx. The following has appeared on the PuTTY
website:
2004-10-26 ANOTHER SECURITY HOLE, fixed in PuTTY 0.56
PuTTY 0.56, released today, fixes a serious security hole which can
allow a server to execute code of its choice on a PuTTY client
connecting to it. In SSH2, the attack can be performed before host
key verification, meaning that even if you trust the server you
think you are connecting to, a different machine could be
impersonating it and could launch the attack before you could tell
the difference. We recommend everybody upgrade to 0.56 as soon as
possible.
That's two really bad holes in three months. I'd like to apologise
to all our users for the inconvenience.
See:
http://www.chiark.greenend.org.uk/~sgtatham/putty/
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BULLETIN BOARD
Did you know that the HPCx website includes a bulletin board? Go to:
http://www.hpcx.ac.uk/support/bulletin/messages/board-topics.html
It would be an exaggeration to say that there has been a lot of
traffic there so far. The helpdesk is our major route for handling
problems, but it has a strict query -> answer protocol. Perhaps
more free-wheeling discussion, involving people from different
projects as well as HPCx staff, might be productive.
So this is an invitation to everyone to pay a visit to the bulletin
board, to post something, and see if it can be a useful resource.
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"CAPABILITY COMPUTING"
The latest edition of our newsletter, "Capability Computing", has been
sent to everyone on our mailing list. If your copy hasn't arrived,
please let us know.
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Regards
--John
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Earlier mailings: http://www.hpcx.ac.uk/support/notices/index.html
To be removed from the mailing list: log into your website account,
go to the "Update" page, and click the "Opt out of user emails"
field; then click "Commit update".
--
John Fisher j.fisher@epcc.ed.ac.uk
HPCx User Administration and Helpdesk
HPCx: http://www.hpcx.ac.uk Helpdesk: support@hpcx.ac.uk
Phone: +44 131 650 5029 Fax: +44 131 650 6555